UwDAS optical cable and audio box combined device for equipment fault monitoring

Abstract

The invention discloses a uwDAS optical cable and audio box combined device for equipment fault monitoring. The device comprises a sensing optical cable, an audio box base, an audio box mandrel, an audio box cover and a sensing optical fiber, the sensing optical fiber is tightly wound on the audio box core shaft, and the audio box core shaft is fixed on the audio box base; the audio box base and the audio box cover are assembled to form an audio box; and the sensing optical cable is connected with the sensing optical fiber in the audio box to form an optical cable and audio box combined device. Through the uwDAS optical cable and audio box combined device, long-distance and high-sensitivity detection of equipment operation sound wave signals can be realized; the system has the characteristics of high sensitivity, stable structure, flexible deployment, continuous coverage, distributed detection, industrial adaptability and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of equipment fault monitoring, and in particular to a uwDAS optical cable and audio box combination device for equipment fault monitoring. Background Art

[0002] The distributed acoustic sensing (DAS) system (uwDAS) based on ultra-weak fiber Bragg Grating (uwFBG) recovers acoustic wave information by detecting the phase information of Fizeau interference between light reflected from adjacent gratings. It is passive, resistant to electromagnetic interference, and has high capacity. Moreover, a single optical fiber can multiplex up to tens of thousands of gratings, enabling long-distance, multi-node distributed data acquisition. It is widely used in many equipment fault monitoring and early warning fields, such as belt conveyor fault detection.

[0003] When fault detection is performed on equipment, fiber optic sensors are laid out along the equipment to accurately analyze its operating status by real-time detection and analysis of its operating sounds. When the sensing unit uses optical cables, it has significant advantages in achieving large-scale coverage, reducing costs, and increasing deployment efficiency. However, due to the presence of the sheath, spiral armor, and other structures of the optical cable itself, the coupling between the internal sensing optical fiber and the outside world is affected, which in turn affects its sensitivity, resulting in a decrease in the accuracy of identifying early minor faults. Therefore, in order to improve the sensing unit's ability to detect tiny abnormal sounds, it is necessary to structurally enhance the sensitivity of the sensing optical fiber. However, most of the current enhanced sensitivity optical fiber sensors are not suitable for deployment in industrial sites or long-term use due to limitations such as the exposed optical fiber being easily damaged, fragile structure, difficult batch processing, and complex installation, and cannot meet the needs of large-scale industrial applications.

[0004] In addition, when the equipment is working, in addition to the operating sound, there are also non-negligible mechanical vibrations. These vibrations usually have strong low-frequency components. Once the sensor unit comes into contact with these vibrations, it will cause significant interference to the detection of the sound signal, posing a challenge to the subsequent separation of the vibration signal and the acoustic signal. Therefore, the use of non-contact sensing of acoustic signals can effectively avoid the interference of vibrations. However, as the distance between the sensor unit and the equipment increases, the quality of the acoustic signal decreases. The existing technology mostly uses fiber optic sensing units with a uniform structure for deployment, and does not perform differentiated optimization for the acoustic characteristics of different operating parts of the equipment. There is a problem of redundant or insufficient signal acquisition capabilities, and it is difficult to achieve a balance between cost, performance and applicability. Therefore, sensitive fiber optic acoustic wave sensors are installed at local key nodes of the equipment, such as drive rollers, bearings, and transfer points, and sensor optical cables are laid in other parts to achieve long-distance, continuous coverage acoustic wave detection. This combined detection method takes into account both deployment costs and local detection performance, and can effectively ensure the safety and efficiency of equipment operation and maintenance. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a uwDAS optical cable and audio box combination device for equipment fault monitoring. Through the uwDAS optical cable and audio box combination device, long-distance and high-sensitivity detection of equipment operation sound wave signals can be achieved; it has the characteristics of high sensitivity, stable structure, flexible deployment, continuous coverage, distributed detection and industrial adaptability.

[0006] The technical solution adopted by the present invention is: A uwDAS optical cable and audio box combination device for equipment fault monitoring, comprising: Sensor optical cable, audio box base, audio box core shaft, audio box cover, sensor optical fiber; The sensing optical fiber is tightly wound around the audio box core shaft, and the audio box core shaft is fixed to the audio box base; The audio box base and the audio box cover are assembled to form the audio box; The sensing optical cable is connected to the sensing optical fiber in the audio box to form an optical cable and audio box combination device.

[0007] The sensing optical cable is fused with the sensing optical fiber in the audio box, and multiple sections of sensing optical cables and multiple audio boxes can be connected in series.

[0008] The cores of the sensing optical cable and the sensing optical fiber are engraved with multiple ultra-weak fiber gratings with an interval of 5 m.

[0009] The audio box base comprises: an optical fiber fixing base, an optical fiber lead-out hole, a tie hole, an embedded wall and a base substrate; The audio box base comprises a core shaft fixing base, which is provided with a core shaft fixing screw hole. The audio box core shaft is fixed to the core shaft fixing base by aligning the screw with the core shaft fixing screw hole.

[0010] The audio box base is provided with an optical fiber lead-out hole, a tie hole, and an optical fiber fixing seat; The sensing optical fiber is led out from the optical fiber lead-out hole and aligned with the optical fiber fixing screw hole with a screw. The metal pressing piece clamps the sensing optical fiber and fixes it on the optical fiber fixing base; the cable tie passes through the cable tie hole to fix the audio box to the bracket near the equipment.

[0011] The optical fiber fixing seat is a rectangular parallelepiped with 1 / 4 of the cylinder dug out, and the center of the dug-out cylinder is aligned with the center of the optical fiber lead-out hole.

[0012] The audio box core shaft includes a supporting core shaft and a foam sensitivity layer. A core shaft installation adjustment hole is left on one end face of the supporting core shaft to facilitate the passage of the core shaft fixing screw; the foam sensitivity layer is pasted on the surface of the supporting core shaft, and the sensing optical fiber is tightly wound on the foam sensitivity layer with a certain prestress.

[0013] A sound pickup hole is opened on the front of the audio box cover, and a hole is opened on each of the two sides and coincides with the optical fiber lead-out hole of the audio box base. The audio box base is tightly embedded in the audio box cover to form an audio box.

[0014] The sensing optical fiber led out of the optical fiber lead-out hole can continue to be wound around the next audio box or fused with the next section of sensing optical cable. The optical cable and audio box combination device is connected to the uwDAS demodulation device for monitoring the operating status of the device.

[0015] In this equipment health monitoring method based on a combination of an optical cable and an audio box, the operating sound of the equipment acts on a sensing optical cable or an audio box, causing the sensing optical cable or the sensing optical fiber to deform, thereby causing a phase change in the light in the fiber core. By demodulating this phase change, the operating sound of the equipment is detected, and its operating status is further monitored.

[0016] This equipment fault location method, based on a combination of an optical cable and an audio box, uses an audio signal generator to generate a fault sound to simulate the fault point. The fault location is then located in two dimensions by analyzing the time difference between the fault sounds measured by different optical sensing cables or audio boxes. Taking the signals measured by three audio boxes as an example, the specific location steps are as follows: Step 1: The three audio boxes are represented by M1, M2, and M3 respectively. A coordinate system is established with M1 as the origin. M2 and M3 are located on the y-axis. The coordinates of M2 are (0, d ), the coordinates of M3 are (0, 2 d ),in, d is the interval between adjacent audio boxes; Step 2: Establish the following system of equations:

[0017] in: is the speed of sound, is the time difference of the signals measured by M1 and M2, is the time difference of the signals measured by M1 and M3, x is the horizontal coordinate of the fault point, y is the vertical coordinate of the fault point, To take the absolute value operation.

[0018] Step 3: Solve the equations in step 2 to get the coordinates of the fault point ( x , y ).

[0019] The present invention provides a uwDAS optical cable and audio box combination device for equipment fault monitoring, and the technical effects are as follows: 1) This invention connects optical cables and audio boxes in series to perform combined detection of equipment operation sounds. By installing audio boxes at key locations on the equipment and laying optical cables at other locations, it achieves highly sensitive, low-cost, and long-distance continuous monitoring of the operating status of the entire line equipment.

[0020] 2) The combined deployment of optical cables and audio boxes not only retains the high sensitivity enhancement capability of audio boxes in key areas, but also fully utilizes the advantages of flexible optical cable deployment and long-distance coverage, taking into account both local precise perception and overall monitoring of the entire line, effectively improving the practicality of the system and the feasibility of the project.

[0021] 3) The core shaft plus shell structure of the audio box, on the one hand, the sound waves pass through the pickup hole and act directly on the core shaft, and the deformation of the core shaft drives the deformation of the optical fiber, thereby improving the sensitivity; on the other hand, the shell effectively reflects the sound waves, and the early reflected sound waves continue to act on the core shaft, to a certain extent enhancing the sound wave signal received by the core shaft, further improving the sensitivity.

[0022] 4) The audio box core shaft features a foam-sensitizing layer attached to the outer surface of the support core shaft. The stiffer support core shaft provides excellent mechanical stability for the audio box, effectively preventing deformation during long-term use. This also increases the overall resonant frequency of the system and broadens its frequency response bandwidth. The outer foam-sensitizing material, due to its lower Young's modulus, can produce greater deformation under the same sound pressure, significantly improving sensitivity. This structure not only strikes a balance between strength and sensitivity, but also offers advantages such as ease of processing and mass production, making it suitable for industrial production and engineering applications.

[0023] 5) The optical sensing cable and the square audio box with the base and the lid embedded in the present invention can be fixed to the bracket near the belt conveyor using cable ties to achieve non-contact sound wave detection, avoiding the strong mechanical vibration interference caused by direct contact with the belt conveyor, and effectively improving the detection purity of the sound wave signal. The embedded base and the lid can effectively reduce the accumulation of pollutants such as environmental dust on the audio box. At the same time, the installation method using cable ties is flexible, simple to construct, and quick to install.

[0024] 6) This invention is not limited to belt conveyor fault detection but is applicable to a wide range of equipment health monitoring, such as rail transit health monitoring, pipeline leak detection, and bridge and tunnel structural health monitoring. It rationally allocates the layout and location of optical cables and audio boxes according to different application scenarios, demonstrating excellent versatility and scalability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will be further described below with reference to the accompanying drawings and examples; Figure 1 This is a schematic diagram of the combined structure of optical cable and audio box.

[0026] Figure 2 This is a structural diagram of the audio box base.

[0027] Figure 3 Schematic diagram of the audio box core shaft structure.

[0028] Figure 4 Schematic diagram of the audio box structure.

[0029] Figure 5 This is the sensing principle diagram of the sensing optical cable / optical fiber.

[0030] Figure 6 Schematic diagram of the structure of the audio box frequency response test device in Example 1.

[0031] Figure 7 This is a frequency response curve diagram of the audio box and bare fiber ring in Example 1.

[0032] Figure 8 This is a structural diagram of the belt conveyor fault location simulation system of the optical cable and audio box combination structure in Example 2.

[0033] Among them, 1-sensing optical cable, 2-audio box base, 3-audio box core shaft, 4-audio box cover, 5-sensing optical fiber, 6-audio box, 7-optical cable and audio box combination device, 8-core shaft fixing base, 9-optical fiber fixing card seat, 10-optical fiber lead-out hole, 11-tie hole, 12-embedded wall, 13-base substrate, 14-core shaft fixing screw hole, 15-optical fiber fixing screw hole, 16-metal pressing piece, 17-support core shaft, 18-foam sensitivity layer, 19-pickup hole; 20-Laser pulse generator, 21-First circulator, 22-uwFBG, 23-Second circulator, 24-Faraday rotator, 25-3×3 coupler, 26-Photodetector, 27-Embedded circuit, 28-Computer, 29-uwDAS demodulation equipment, 30-Audio signal generator, 31-Sound pressure meter, 32-Bare fiber ring, 33-Sound absorbing box, 34-Shock-absorbing sponge, 35-Mandrel mounting adjustment hole. DETAILED DESCRIPTION

[0034] like Figures 1 to 4 As shown, the present invention provides a uwDAS optical cable and audio box combination device for equipment fault monitoring, which includes: a sensing optical cable 1, an audio box base 2, an audio box core shaft 3, an audio box cover 4 and a sensing optical fiber 5.

[0035] The sensor optical cable 1 is as Figure 1 As shown in the figure, it is a vibration optical cable with multiple ultra-weak fiber Bragg gratings (uwFBGs) with a core space of 5 m. The sensing fiber 5 is as shown in the figure. Figure 3 As shown in the figure, it is a vibrating optical fiber with multiple uwFBGs engraved on the core at 5 m intervals. The sensing principle of the sensing optical cable 1 and the sensing optical fiber 5 is as follows: Figure 5 As shown in the figure, a laser pulse generator 20, consisting of a narrowband laser (NLL), a semiconductor amplifier (SOA), and an erbium-doped fiber amplifier (EDFA), outputs an optical pulse signal. The optical pulse signal passes through a first circulator 21 and is sequentially coupled into a uwFBG 22, where a very small portion of the optical signal is reflected. The remaining optical pulse continues to transmit. The reflected optical signal is output from the first circulator 21, passes through a second circulator 23, and is coupled into a Faraday rotator 24 with an arm length difference equal to the spacing between adjacent uwFBGs (5 m) for distance compensation. This causes the reflected optical signals of two adjacent uwFBGs 22 to interfere in a 3×3 coupler 25. The signals are then split into three output paths and received by a photodetector 26. The collected signals are demodulated and calculated by an embedded circuit 27, and the processing results are displayed on a computer 28. According to the uwFBG sensing principle, when the optical fiber between two adjacent uwFBGs 22 is subjected to external influences such as acoustic waves or stress, the phase of the pulsed light within the fiber changes. Subsequent demodulation allows quantitative analysis of the magnitude of this phase change, thereby determining the change in the physical quantity acting on the sensing fiber. Furthermore, the interference within the 3×3 coupler 25 occurs only with the reflected light signals from the two adjacent uwFBGs 22. The demodulated phase change is related only to the sensing fiber between the two uwFBGs 22. This means that the optical fiber between the two adjacent uwFBGs 22 can be considered an independent sensing unit.

[0036] like Figure 2As shown, the audio box base 2 is made of aluminum and includes a core shaft fixing base 8, an optical fiber fixing base 9, an optical fiber lead-out hole 10, a tie hole 11, an embedded wall 12 and a base substrate 13. The core shaft fixing base 8 has a diameter of 75 mm, and four core shaft fixing screw holes 14 are evenly distributed 10 mm from the edge of the core shaft fixing base 8. The optical fiber fixing base 9 is 9 mm from the proximal end of the embedded wall 12. It is a rectangular parallelepiped with a length of 20 mm, a width of 15 mm, and a height of 7.17 mm, with 1 / 4 of a cylinder with a diameter of 8 mm and a length of 15 mm hollowed out. The center of the hollowed-out cylinder is aligned with the center of the optical fiber lead-out hole 10. The optical fiber fixing base 9 and the metal pressing plate 16 with a length of 20 mm, a width of 15 mm, and a height of 0.5 mm have aligned optical fiber fixing screw holes 15. Half of the optical fiber lead-out hole 10 with a diameter of 8 mm is located on the embedded wall 12. The cable tie hole 11 is 20 mm long and 5 mm wide and is located between the two sides of the base substrate 13. The embedded wall 12 is 168 mm long, 99 mm wide, and 10 mm high; the base substrate 13 is 174 mm long, 105 mm wide, and 15 mm high.

[0037] like Figure 3 As shown, the audio box core shaft 3 comprises a supporting core shaft 17 and a foam sensitivity layer 18. The supporting core shaft 17 is made of plastic, with two end faces having a diameter of 75 mm and a frame with a diameter of 61 mm and a height of 45 mm. One end face has a core shaft mounting adjustment hole 35 that divides a circular ring with an outer diameter of 36 mm and an inner diameter of 27.5 mm into four equal parts, facilitating rotational adjustment of the supporting core shaft 17 when fixed. The foam sensitivity layer 18, affixed to the frame, is 5 mm thick and has a Young's modulus of approximately 16.5 MPa and a Poisson's ratio of approximately 0.35. The sensing fiber 5 is tightly wound around the foam sensitivity layer 18 with a certain prestress. Ten meters of sensing fiber 5 are wound around each audio box core shaft 3, ensuring that two uwFBGs are always wound around each audio box core shaft 3, making each audio box 6 an independent sensing unit.

[0038] like Figure 4 As shown, the audio box cover 4 is 170 mm long, 100 mm wide and 48 mm high, with 12 sound pickup holes 19 on one front side, each sound pickup hole 19 is 5 mm long and 30 mm high, the interval between two adjacent sound pickup holes 19 is 5 mm, and the distance between the sound pickup holes 19 at both ends and the edge of the audio box cover 4 is 20 mm; a hole with a diameter of 8 mm is opened on each side of the audio box cover 4 as an optical fiber lead-out hole 10, which coincides with the optical fiber lead-out hole 10 on the embedded wall 12.

[0039] like Figure 1As shown, the optical cable and audio box combination device 7 is a structure that fuses the sensing optical cable 1 and the sensing optical fiber 5 in the audio box 6 together. After the sensing optical fiber 5 of each audio box 6 is wound, it is clamped and fixed to the optical fiber fixing base 9 by the metal pressing plate 16 and led out from the optical fiber lead-out hole 10. The audio box base 2 is tightly embedded in the audio box cover 4 to form the audio box 6. According to the detection requirements, the sensing optical fiber 5 led out of the optical fiber lead-out hole 10 can continue to be wound around the next audio box 6 or fused with the sensing optical cable 1. The length of the sensing optical cable 1 is determined according to the test requirements. Finally, the sensing optical cable 1 or the sensing optical fiber 5 at one end of the optical cable and audio box combination structure 7 is connected to the uwDAS demodulation device 29 to monitor the operating status of the equipment.

[0040] The uwDAS demodulation device 29 is produced by Yichang Ruichuan Optoelectronic Technology Co., Ltd. and has the model number RS-HFBGA-05. The laser emits a light pulse along the optical fiber, which is directionally reflected at the grating position and then interferes after phase compensation. This interference carries the acoustic vibration information along the line where the optical cable and audio box combination device 7 are laid out. The frequency, phase and amplitude information of the signal are extracted by processing the collected data.

[0041] The performance test device of audio box 6 is as follows Figure 6 As shown, it includes a uwDAS demodulator 29, a computer 28, an audio signal generator 30, a sound pressure meter 31, a bare fiber ring 32, and an audio box 6. Among them, the bare fiber ring 32 is the control group of the audio box 6, and the two are different grid points on an optical fiber. During the test, the bare fiber ring 32 and the audio box 6 are placed on a flat shock-absorbing sponge 34 and placed together in a sound-absorbing box 33 to reduce the interference of external vibrations and echoes. The sensing optical fiber 5 is connected to the uwDAS demodulator 29, and the uwDAS demodulator 29 is connected to the computer 28 to display the test signal in real time. The computer 28 drives the audio signal generator 30 to generate the required sound wave signal and makes the sound wave incident radially along the audio box 6. The sound pressure meter 31 is placed at a place with the same sound pressure as the audio box 6 for performance tests such as frequency response.

[0042] The belt conveyor fault location simulation system based on the optical cable and audio box combination device 7 is as follows Figure 8 As shown, the system includes a uwDAS demodulator 29, a computer 28, an audio signal generator 30, and an optical cable and audio box assembly 7. All optical cables and audio boxes 6 are arranged at equal intervals in a straight line. The audio signal generator 30 generates a belt conveyor fault sound to simulate the belt conveyor fault point. By analyzing the time difference of the fault sound measured by different optical cables or audio boxes 6, the fault position is located in a two-dimensional plane. Taking the signals measured by three audio boxes 6 as an example, the specific positioning steps are as follows: Step 1: The three audio boxes 6 are represented by M1, M2, and M3 respectively. A coordinate system is established with M1 as the origin. M2 and M3 are located on the y-axis. The coordinates of M2 are (0,d ), the coordinates of M3 are (0, 2 d ),in d The interval between adjacent audio boxes.

[0043] Step 2: According to the geometric relationship, we have the following set of equations: ; in: is the speed of sound, usually 343 m / s, is the time difference of the signals measured by M1 and M2, is the time difference of the signals measured by M1 and M3, x is the horizontal coordinate of the fault point, y is the vertical coordinate of the fault point, To take the absolute value operation.

[0044] Step 3: Solve the equations in step 2 to get the coordinates of the fault point ( x , y ).

[0045] Through the above implementation, by tightly winding the sensing optical fiber 5 around the audio box core shaft 3 and fixing it to the base 2 of the audio box 6, the effective sensitivity of the sensor is achieved, and efficient detection of tiny sounds in key parts of the belt conveyor can be achieved. At the same time, the detection method of the optical cable and audio box combination device 7 realizes high-sensitivity, low-cost, long-distance continuous monitoring of the operating status of the entire belt conveyor line, and can achieve accurate fault location, which has important application value in the field of industrial equipment health monitoring.

[0046] Example 1. Audio box frequency response experiment: according to Figure 6 The test device shown in the figure uses an audio signal generator 30 to generate sinusoidal signals in the frequency range of 100 to 2000 Hz, with a step size of 50 Hz. The phase information obtained by the computer 28 and the corresponding sound pressure meter value at each frequency are recorded. The ratio of phase to sound pressure is the sound pressure sensitivity at that frequency. The sound pressure sensitivity of the bare fiber ring and the audio box is tested as a function of frequency to obtain a frequency response curve, as shown in the figure below. Figure 7 As shown. Figure 7 It was found that the average sound pressure sensitivities of the audio box and bare fiber ring in the frequency range of 100~2000 Hz were -117.6 dB re 1 rad / uPa and -138.6 dB re 1rad / uPa, respectively. The sensitivity of the audio box structure proposed in the present invention is greatly improved compared with the bare fiber ring, which enhances the system's ability to capture weak signals.

[0047] Example 2. Belt conveyor fault location experiment of the optical cable and audio box combination structure: according to Figure 8 The belt conveyor fault location simulation system shown in the figure uses an audio signal generator 30 to output a sound signal to simulate a belt conveyor fault. The position of the audio signal generator 30 at that moment is recorded as the actual fault location. The coordinates of the fault location are calculated as the estimated location based on the signal time difference measured by different optical cables or audio boxes. Similarly, the position of the audio signal generator 30 is varied, and the coordinates of each fault location are calculated. The Euclidean distance between the actual and estimated locations is used as the location error. Multiple experiments were conducted, using three audio boxes spaced 0.5 m apart as an example. The coordinates of the three audio boxes M1, M2, and M3 are (0, 0) m, (0, 0.5) m, and (0, 1) m, respectively. The fault location results shown in Table 1 were obtained.

[0048] Table 1 Fault location results

[0049] Table 1 shows that the average positioning error is approximately 0.1586 m, which is comparable to the size of the audio box 6 and audio signal generator 30. Therefore, when detecting belt conveyor faults, the fault location can be confined to a smaller area. During this simulation, the manual placement of the audio box 6 and audio signal generator 30, as well as the volume of the audio box 6 and audio signal generator 30 themselves, made it difficult to achieve millimeter-level positioning accuracy in actual operation. This resulted in inevitable deviations from the true coordinates, which were amplified during fault location, increasing the error. Furthermore, sound wave propagation is affected by multipath effects caused by reflections from walls and floors, which interfere with the calculation of the arrival time difference between the sound waves from the audio boxes 6 and also affect positioning accuracy to a certain extent. In actual engineering applications, positioning accuracy can be further improved through more standardized installation and position calibration methods, as well as the design of anti-interference algorithms.

Claims

1. A uwDAS optical cable and audio box combination device for equipment fault monitoring, characterized in that The device includes: Sensing optical cable (1), audio box base (2), audio box core shaft (3), audio box cover (4), sensing optical fiber (5); The sensing optical fiber (5) is tightly wound on the audio box core shaft (3), and the audio box core shaft (3) is fixed on the audio box base (2); The audio box base (2) and the audio box cover (4) are assembled to form an audio box (6); The sensing optical cable (1) is connected to the sensing optical fiber (5) in the audio box (6) to form an optical cable and audio box combination device (7).

2. The uwDAS optical cable and audio box combination device for equipment fault monitoring according to claim 1, characterized in that: The sensing optical cable (1) is fused with the sensing optical fiber (5) in the audio box (6), and multiple sections of sensing optical cables (1) and multiple audio boxes (6) can be connected in series.

3. The uwDAS optical cable and audio box combination device for equipment fault monitoring according to claim 1, characterized in that: The cores of the sensing optical cable (1) and the sensing optical fiber (5) are both engraved with a plurality of ultra-weak fiber gratings with an interval of 5 m.

4. The uwDAS optical cable and audio box combination device for equipment fault monitoring according to claim 1, characterized in that: The audio box base (2) comprises a core shaft fixing base (8), the core shaft fixing base (8) is provided with a core shaft fixing screw hole (14), and the audio box core shaft (3) is fixed on the core shaft fixing base (8).

5. The uwDAS optical cable and audio box combination device for equipment fault monitoring according to claim 4, characterized in that: The audio box base (2) is provided with an optical fiber lead-out hole (10), a tie hole (11), and an optical fiber fixing seat (9); The sensing optical fiber (5) is led out from the optical fiber lead-out hole (10), and the metal pressing piece (16) clamps and fixes the sensing optical fiber (5) on the optical fiber fixing base (9); and the cable tie passes through the cable tie hole (11) to fix the audio box (6) near the device.

6. The uwDAS optical cable and audio box combination device for equipment fault monitoring according to claim 1, characterized in that: The audio box core shaft (3) comprises a supporting core shaft (17) and a foam sensitization layer (18), and a core shaft installation adjustment hole (35) is left on one end face of the supporting core shaft (17); the foam sensitization layer (18) is adhered to the surface of the supporting core shaft (17), and the sensing optical fiber (5) is tightly wound on the foam sensitization layer (18) with a certain prestress.

7. The uwDAS optical cable and audio box combination device for equipment fault monitoring according to claim 1, characterized in that: A sound pickup hole (19) is formed on one surface of the audio box cover (4), and a hole is formed on each of the two side surfaces and overlaps with the optical fiber lead-out hole (10) of the audio box base (2). The audio box base (2) is embedded in the audio box cover (4) to form an audio box (6).

8. The uwDAS optical cable and audio box combination device for equipment fault monitoring according to claim 5, characterized in that: The sensing optical fiber (5) led out of the optical fiber lead-out hole (10) can continue to be wound around the next audio box (6) or fused with the next section of sensing optical cable. The optical cable and audio box combination device (7) is connected to the uwDAS demodulation device (29) for monitoring the operating status of the device.

9. The device health monitoring method of the uwDAS optical cable and audio box combination device according to any one of claims 1 to 8, characterized in that: The operating sound of the device acts on the sensing optical cable (1) or the audio box (6), causing the sensing optical cable (1) or the sensing optical fiber (5) to deform, thereby causing a phase change of the light in the fiber core. By demodulating this phase change, the operating sound of the device is detected, and its operating status is further monitored.

10. A device fault locating method according to any one of claims 1 to 8, characterized in that: The audio signal generator (30) generates a device fault sound to simulate the device fault occurrence point. By analyzing the time difference of the fault sound measured by different sensor optical cables (1) or audio boxes (6), the fault position is located in a two-dimensional plane. In the case of the signals measured by three audio boxes (6), the specific positioning steps are as follows: Step 1: The three audio boxes (6) are represented by M1, M2, and M3 respectively. A coordinate system is established with M1 as the origin. M2 and M3 are located on the y-axis. The coordinates of M2 are (0, d ), the coordinates of M3 are (0, 2 d ),in, d is the interval between adjacent audio boxes; Step 2: Establish the following system of equations: ； in: is the speed of sound, is the time difference of the signals measured by M1 and M2, is the time difference of the signals measured by M1 and M3, x is the horizontal coordinate of the fault point, y is the vertical coordinate of the fault point, To take the absolute value operation; Step 3: Solve the equations in step 2 to get the coordinates of the fault point ( x , y ).

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